Stabilization System, Implant, And Methods For Preventing Relative Motion Between Sections Of Tissue

ABSTRACT

A stabilization system and implant for preventing relative motion between tissue sections of a patient, for example, an ilium and a sacrum defining a sacroiliac joint. The stabilization system comprises an implant comprising an elongate trunk, a proximal anchor configured to be positioned within the ilium, and a distal anchor configured to be positioned within the sacrum. The proximal anchor comprises a deformable feature configured to engage the ilium and the distal anchor comprises an expandable member configured to engage the sacrum. The stabilization system further comprises a tool removably coupled to the anchor to insert the implant in the patient and selectively engage the anchors with the respective bones. The implant is configured to be implanted through a minimally invasive incision.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present patent application claims priority to and all the benefitsof U.S. Provisional Patent Application No. 62/488,417, filed on Apr. 21,2017, the disclosure of which is hereby incorporated by reference in itsentirety.

TECHNICAL FIELD

The present disclosure is related generally to an implant for astabilization system for securing two sections of tissue. Moreparticularly, but not exclusively, the present disclosure is directed tostabilization system, an implant, and methods for preventing relativemotion between a first bone and a second bone, for example, an ilium anda sacrum defining a sacroiliac (SI) joint during minimally invasivesurgery.

BACKGROUND

A number of different medical procedures involve securing sections oftissue. For example, for an individual to receive relief from pain inthe pelvic region or lower back, a recognized treatment is to perform SIjoint fusion in which the sacrum is fixed to the ilium. Anothersituation when it is indicated to secure two sections of tissue isfixation of a fractured bone. Still further, spinal fusion includingfixation of adjacent vertebrae is also a procedure of particularinterest.

Securing adjacent sections of bone (or two adjacent bones) may includedrilling a bore that at least partially extends through each of theadjacent sections of the bone. An elongated implant is seated andsecured within the bore. A portion of the implant is positioned in oneof the sections of the bone (e.g., a first bone), and another portion ofthe implant is positioned within another section of the bone (e.g., asecond bone). The implant, and sometimes plural implants, preventsmovement of the sections of the bone. The adjacent surfaces of thesections of the bone may fuse together to form a single bone. The fusionincreases the strength of the bond between the two sections of bone.

Known systems and methods of securing sections of tissue are associatedwith several disadvantages. For example, eliminating relative movementbetween the sections of the bone often requires the implant to berelatively large in size to ensure adequate contact area between theimplant and the sections of the bone. It readily follows that arelatively larger implant requires a commensurately larger incision. Theinvasiveness of the larger incision may lead to increased healing timeand risk of infection.

Therefore, there is a need in the art for a stabilization system and animplant for the stabilization system designed to overcome one or more ofthe aforementioned disadvantages

SUMMARY

One aspect of the present disclosure is directed toward an implant for aminimally invasive bone stabilization system for preventing relativemotion between an ilium and a sacrum. The implant comprises an elongatetrunk defined between a proximal end configured to be positioned withinthe ilium, a distal end configured to be positioned within the sacrum.The elongate trunk extends between the ilium and the sacrum. A boreextends through the elongate trunk. A longitudinal axis may be definedbetween the proximal and distal ends, and a periphery may be defined byan outer surface of the elongate trunk. The implant further comprises aproximal anchor comprising at least one deformable feature. Thedeformable feature is adapted to move between an initial configurationin which the deformable feature is within the periphery of the elongatetrunk, and a deployed configuration in which at least a portion of thedeformable feature extends outwardly beyond the periphery of theelongate trunk relative to the longitudinal axis to engage the ilium.Additionally, the implant comprises a distal anchor coupled to theelongate trunk. The distal anchor comprising an expandable memberdefining an interior in fluid communication with the bore of theelongate trunk. The expandable member is adapted to receive curablematerial to move between a collapsed state in which the expandablemember is within the periphery of the elongate trunk, and an expandedstate in which at least a portion of the expandable member extendsoutwardly beyond the periphery of the elongate trunk relative to thelongitudinal axis to engage the sacrum.

According to certain aspects of the present disclosure, the implantcomprises a stem extending proximally from the proximal end of theelongate trunk. The stem comprises driven features configured to engagecomplimentary drive features of an insertion tool. The proximal anchorcomprises engagement features coupled to the elongate trunk andconfigured to engage complimentary engagement features of the insertiontool. The deformable features may be circumferentially arranged aboutthe outer surface of the elongate trunk. The deformable features areadapted to buckle in response to compressive loads applied to theproximal anchor such that at least a portion of the deformable featuresextend beyond the periphery of the elongate trunk relative to thelongitudinal axis to engage the ilium.

According to certain aspects of the present disclosure, the minimallyinvasive bone stabilization system includes the insertion toolcomprising a driver configured to receive a rotational input, a firstshaft comprising a distal end and engagement features at the distal end,a second shaft coaxially arranged within the first shaft. The secondshaft includes a proximal end coupled to the driver, a distal endopposite the proximal end, drive features near the distal end, and alumen extending through the second shaft.

A method for preventing relative motion between the ilium and the sacrumwith the implant is also disclosed. The method comprises the steps ofcreating a minimally invasive incision within skin. An access cannula ispositioned through the minimally invasive incision. A borehole isresected through the ilium and into the sacrum through the accesscannula. The implant is positioned within the borehole such that theproximal anchor is disposed in the ilium and the distal anchor isdisposed in the sacrum. The insertion tool removably coupled to theimplant is operated to apply a compressive force to the proximal anchoralong the longitudinal axis. The proximal anchor moves from the initialconfiguration in which the proximal anchor is within the periphery ofthe elongate trunk, to the deployed configuration in which at least aportion of the deformable feature of the proximal anchor extendsoutwardly beyond the periphery of the elongate trunk relative to thelongitudinal axis to engage the ilium. Curable material is injectedthrough the bore and into the expandable member to move the expandablemember between the collapsed state in which the expandable member iswithin the periphery of the elongate trunk, and the expanded state inwhich at least a portion of the expandable member extends outwardlybeyond the periphery of the elongate trunk relative to the longitudinalaxis to engage the sacrum

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure is pointed out with particularity in the claims. Theabove and further features and benefits of the disclosure are understoodby the following Detailed Description taken in conjunction with theaccompanying drawings.

FIG. 1 is a perspective view of an implant and an insertion tool.

FIG. 2 is a cross sectional view of the implant of FIG. 1.

FIG. 3A is a perspective view of the implant of FIG. 1 with anexpandable member forming a portion of a distal anchor removed.

FIG. 3B is a partial perspective view of the implant of FIG. 1 showing aproximal anchor.

FIG. 4 is an exploded view of the insertion tool of FIG. 1 with adelivery cannula configured to be positioned within a lumen of theinsertion tool.

FIG. 5 is a cross sectional view of the implant and the insertion toolof FIG. 1.

FIG. 6 is an enlarged cross sectional view showing the implant securedto a distal end of the insertion tool.

FIG. 7 is a cross sectional view of the implant and the insertion toolof FIG. 6 with the implant positioned within first and second tissuesections. The proximal anchor is in the initial configuration and thedistal anchor is in the collapsed state.

FIG. 8 is a perspective view of the implant of FIG. 1 with the proximalanchor in the deployed configuration and the distal anchor in theexpanded state.

FIG. 9 is a cross sectional view of the implant of FIG. 8 with theproximal anchor in the deployed configuration within the first tissuesection and the distal anchor in the expanded state within the secondtissue section.

FIG. 10 is a perspective view of an implant in accordance with anotherexemplary embodiment of the present disclosure.

FIG. 11 is a perspective view of an implant in accordance with anotherexemplary embodiment of the present disclosure.

FIG. 12 is a cross section view of an implant in accordance with anotherexemplary embodiment of the present disclosure.

FIGS. 13A, 13B and 13C is a cross sectional view of the implant withinthe first and second tissue sections, as shown in FIG. 9, and furtherillustrating directing of material(s) into or between the first andsecond tissue sections at various points along a length of the implant.

FIG. 14 is an elevation view of an access cannula and access needlepositioned through an incision within skin.

FIG. 15 is an elevation view of an access cannula of FIG. 14 with adrill used to resect a borehole in the first and second tissue sections.

FIGS. 16 and 17 illustrate steps of positioning the implant through theaccess cannula and into the borehole using the insertion tool.

FIG. 18 is a schematic view of a sacroiliac joint of a patient with aplurality of implants positioned within the SI joint and each of theimplants depicting a different step of an exemplary method for fixingthe ilium and sacrum.

DETAILED DESCRIPTION

FIG. 1 depicts an insertion tool 30 and an implant 76 for a minimallyinvasive stabilization system. The implant 76 is configured to beinserted into a patient to hold two sections of tissue together. FIGS.7, 9 and 13A-13C, for example, show a first tissue section 122 and asecond tissue section 124 separated by an interface 326 or joint space.The first and second tissue sections 122, 124 may be a first and secondbone, respectively. In one example to be described throughout thepresent disclosure, the first tissue section 122 is an ilium, the secondtissue section 124 is a sacrum, and the interface 326 may generallydefine the SI joint. It is to be understood that the implant 76 may beused with other surgical procedures to prevent relative motion ofpatient anatomy, for example, spinal fusion, ankle fusion, foot fusion,wrist fusion, hand fusion, fracture fixation, dislocation reduction, andthe like. In a manner to be described in more detail, the implant 76 isremovably coupled to the tool 30. The tool 30 is operated by a user toposition and deploy the implant 76 to prevent relative motion betweenthe sacrum and the ilium.

The implant 76, best shown in FIGS. 2, 3A, 3B and 8, includes anelongate trunk 90. The trunk 90 is defined between a proximal end 302configured to be positioned within the first tissue section 122 and adistal end 304 configured to be positioned within the second tissuesection 124. The trunk 90 extends between the first tissue section 122and the second tissue section 124. A proximal anchor 86 is locatedproximally from the proximal end 302 of trunk 90, and a distal anchor106 is located distally to the distal end 304 of the trunk 90.(“Proximal” is understood to mean towards the practitioner, away fromthe site in which the implant 76 is to be seated; and “distal” isunderstood to mean away from the practitioner holding the tool 30,towards the site in which the implant 76 is to be seated.) In a mannerto be described, the tool 30 is used to deploy the proximal anchor 86,and in certain embodiments the distal anchor 106. Once the proximal anddistal anchors 86, 106 are deployed, the implant 76 secures the firstand second tissue sections 122, 124.

The implant 76 is shaped so that trunk 90 is elongate in shape. Thetrunk 90 includes a periphery 306 defined by an outer surface 308 of thetrunk 90. In the illustrated embodiment, the trunk 90 is cylindrical andhas a length defined between the proximal and distal ends 302, 304 and adiameter defined by the periphery 306. In other words, FIG. 3A shows theouter surface 308 extending circumferentially to define the periphery306. The proximal anchor 86 may be a tubular shaped structure thatextends proximally from the proximal end 302 of trunk 90. In theillustrated embodiment, at least a portion of the proximal anchor 86 isformed integrally with the trunk 90. The proximal anchor 86 comprises atleast one deformable feature 310 that is, at least initially, within theperiphery 306 of the trunk 90. In certain embodiments, the implant 76 isshaped so that the outer diameter of proximal anchor 86 and theperiphery 306 of the trunk 90 are initially equal. The deformablefeature 310 of the proximal anchor 86 is adapted to move between aninitial configuration (shown in FIGS. 2 and 3) in which the deformablefeature 310 is within the periphery 306 of the trunk 90, and a deployedconfiguration (shown in FIGS. 8 and 9) in which at least a portion ofthe deformable feature 310 extends outwardly beyond the periphery 306relative to the longitudinal axis 300 to engage the first tissue section122, e.g., the ilium. The distal anchor 106 is coupled to the trunk 90and comprises an expandable member 312. The expandable member 312 isadapted to receive injectable material to move between a collapsed state(shown in FIGS. 6 and 7) in which the expandable member 312 is withinthe periphery 306 of the trunk 90, and an expanded state (shown in FIGS.8 and 9) in which at least a portion of the expandable member 312extends outwardly beyond the periphery 306 of the trunk 90 relative tothe longitudinal axis 300 to engage the second tissue section 124; e.g.,the sacrum. Thus, prior to positioning the implant 76 within thepatient, the proximal and distal anchors 86, 106 are within theperiphery 306 to minimize the axial profile of the implant 76 andfacilitate surgery that is less or minimally invasive. Relative to knownsystem with diameters of 10, 12 or greater millimeters (mm) (and/orrequiring the use of a tissue dilator), the implant 76 of the presentdisclosure advantageously has smaller diameters that provides forpercutaneous placement through a minimally invasive incision. Exemplarydiameters of the implant 76 include less than 10 mm, and moreparticularly less than 7 mm, and even more particularly less than 4 mm.Further, the component of tool 30 used to position the implant 76 neednot require a diameter larger than that of the implant 76 itself.Consequently, the relatively smaller incision and borehole exposes thepatient to less trauma.

As used herein, injectable material may include any material suitablefor injection into the patient for use with the stabilization systemand/or as part of the methods disclosed herein. The injectable materialmay include a curable material, for example, a biocompatible curablematerial (bone cement). Exemplary curable materials includenon-resorbable curable materials such as polymethylmethacrylate (PMMA)or glass ionomer cements, or resorbable material such as calciumphosphate. The injectable material may include a bone growth material(e.g., autograft bone, allograph bone, and/or synthetic material thatfosters bone growth). The injectable material may include therapeuticagents, for example, a pharmacologic that reduces infection or tissueinflammation). Other injectable materials suitable with the presentsystem and methods are contemplated, and it is also understood thatcombinations of the aforementioned injectable materials may be utilized(e.g., calcium phosphate with demineralized bone matrix and bioglass).In alternative embodiments, the material received within the interior314 of the expandable member 312 is not injected, but rather packed witha tamp or otherwise provided in a suitable manner.

With reference to FIGS. 3A and 3B, the proximal anchor 86 includes aplurality of apertures 104. The apertures 104 extend through the anchor86, and may be circumferentially arranged and arcuately spaced apartfrom each other on an outer surface 309 of the proximal anchor 86integrally formed with the outer surface 308 of the trunk 90. In otherwords, the outer surfaces 308, 309 may be a singular, continuousstructure, as shown, but are separately identified to delineate theportion of the outer surface defining the proximal anchor 86. Theapertures 104 define a deformable feature 310 interposed between eachadjacent pair of apertures 104. Each of the apertures 104 may be oval inshape and comprise a major axis 316 and a minor axis 318. The implant 76is formed so that the major axes 316 of apertures 104 are parallel tothe longitudinal axis 300 through the implant 76, as shown in FIG. 3B.In a manner to be described, the apertures 104 are configured tolocalize stresses to the deformable feature 310 from compressive loadsapplied to the proximal anchor 86 to induce deformation of thedeformable feature 310 and move the deformable feature 310 from theinitial configuration to the deployed configuration. Each of thedeformable features define a width, where the width is smallest at aposition between the minor axes 318 of adjacent pairs of apertures 104such that the localized stresses induce buckling to the deformablefeatures 310 at the widths. In another exemplary embodiment, a pluralityof slots (not shown) may be circumferentially arranged and spaced apartfrom each other on the outer surface 309 of the proximal anchor 86. Theslots define the deformable feature 310 interposed between each adjacentpair of the slots with the deformable feature 310 being strut-like inshape. The localized stresses induce bowing of the struts with each ofthe bowed struts including an apex in the deployed configuration withthe apex extending beyond the periphery 306 of the trunk 90 relative tothe longitudinal axis 300. In still another exemplary embodiment, theproximal anchor 86 may take the appearance of an annular cage in atleast some respects similar to a cardiovascular stent. The annular cageinclude a grid-like pattern of structural members (i.e., the deformablefeatures 310) with interstitial spaces (i.e., the apertures 104). Thecage is configured to deform, deflect, buckle, bow, and/or otherwisedeform in response to the compressive loads applied to the proximalanchor 86 such that at least a portion of the cage extends beyond theperiphery 306 of the trunk 90 relative to the longitudinal axis 300.

For still another example, the proximal anchor 86 may include opposingwings configured to deflect outwardly in response to the screw-likemember being axially advanced on contact with the opposing wings. It isto be understood that deformation may include deflection of at least aportion of the proximal anchor 86. For still yet another example, theproximal anchor 86 may include a scissor-like jack having two opposingsurfaces configured to move in opposite directions in response to thescrew-like member being axially advanced.

The proximal end of proximal anchor 86 may be castellated. Specificallyplural arcuately spaced apart tabs 87, as shown in FIG. 3A and 3B,extend proximally from the proximal end of the proximal anchor 86. A cap78 is disposed over the proximal end of proximal anchor 86. The cap 78is formed to have a base 79. The base 79 is formed with slots 80 thatextend inwardly from a distally directed face of the base 79. The slots80 are dimensioned to receive the tabs 87 defining the castellatedproximal end of the proximal anchor 86. The seating of the tabs 87 inthe slots 80 prevents relative rotation of cap 78 and the trunk 90. Thecap 78 may include cylindrically shaped skirt 82. The skirt 82 extendsdistally forward from an inner perimeter of the base 79. The skirt 82defines a circular void space or cavity 320 for purposes to bedescribed. The cap 78 is further formed so the proximal end of the base79 is formed to have an engagement feature, such as teeth 81 identifiedin FIGS. 3A and 3B, adapted to receive a complimentary engagementfeature, such as complimentary teeth of the tool 30 (see FIG. 6). Thecap 78 includes a lid 83, identified only in FIG. 2, extending over thetop of skirt 82 to define an aperture (not identified).

With reference to FIG. 2, the implant 76 also includes a stem 88. Thestem 88, like the proximal anchor 86, extends proximally from theproximal end 302 of the trunk 90. A diameter of the stem 88 is less thanthe diameter of the trunk 90 such that the stem 88 may be disposed inthe void space 320 internal to the proximal anchor 86 and within theskirt 82 of the cap 78. The stem 88 may extend through the aperture ofthe lid 83 of the cap 78. The stem 88 may be centered on a longitudinalaxis 300 of the trunk 90. In the illustrated embodiment, a proximal endof the stem 88 is located distally forward of the proximal end ofproximal anchor 86. The stem 88 is formed so that a driven feature, suchas threads 89, extends around the outer surface of the stem 88. Thedriven feature is configure to engage a drive feature, such ascomplimentary threading 64, of the tool 30.

Turning to the distal anchor 106 of the implant 76, a neck 92 extendsdistally forward from the distal end 304 of the trunk 90. Referring toFIGS. 2, 3A and 3B, the neck 92 may be cylindrical in shape andcomprises a diameter less than the diameter of the trunk 90 andseparated by a distally directed step surface defining the distal end304 of the trunk 90. The implant 76 may include a head 94 distal to theneck 92. The head 94 may be cylindrical in shape and centered on thelongitudinal axis 300. A gripping feature is coupled to the neck 92 inorder to facilitate axial retention of the implant 76 in the sacrum 124.One example of the gripping feature is ribs 96, one each identified inFIGS. 2 and 3, which are coupled to and extend radially outwardly fromthe neck 92. The ribs 96 extend arcuately around the outer surface ofthe neck 92. In the illustrated embodiment, implant 76 is formed to haveplural ribs 96 longitudinally spaced apart from each other along thehead 94. In the illustrated embodiment, the implant 76 may be formed sothat multiple ribs 96 may be spaced axially from each other such thatthe ribs 96 form multiple rows. The ends of these ribs 96 are angularlyspaced apart from each other. The ribs 96 may have an outer diameterapproximately equal to the outer diameter of the neck 92. Alternativegripping features may be used instead of or in combination with the rib96. For example, the gripping feature may include a porous surface, acoating, a knurled surface, a circumferential groove, threads, aroughened surface of neck 92 and the head 94, and an anchor similar tothe proximal anchor. The gripping features provide enhanced axialretention between the implant 76 and the curable material to be curedabout the head 94 in a manner to be described.

With reference to FIGS. 2 and 6, the implant 76 is also formed to have abore 102 that extends proximally to distally along the longitudinal axis300 of the implant 76. The bore 102 may be in communication with acoaxial counterbore 98 extending distally forward from a proximal end ofstem 88 to a distal end of the stem 88 (e.g., the proximal end 302 ofthe trunk 90). The counterbore 98 is understood to be larger in diameterthan bore 102. The bore 102 extends from through the trunk 90, throughthe neck 92 and head to an opening in the head 94.

The distal anchor 106 is coupled to the trunk 90 and comprises anexpandable member 312 that defines an interior 314 in fluidcommunication with the bore 102 of the trunk 90. The expandable member312 is coupled to the neck 92 such that the head 94 and each rib 96 islocated within the interior 314 of the expandable member 312. Forexample, the expandable member 312 may be a flexible, inflatableballoon. In some versions of the disclosure, the expandable member 312is formed from a thermoplastic polyurethane or other elastomericmaterial. The expandable member 312 is shaped to have a narrowed portion108, identified only in FIG. 9. The narrowed portion 108 is shaped totightly fit around neck 92. An adhesive, clamp, or other joining meansmay be used to hold the narrowed portion 108 fast to the neck 92. Distalto the narrowed portion 108, the expandable member 312 is shaped to havean expanding portion 110, identified in FIGS. 2, 10 and 11. Theexpanding portion 110 of the expandable member 312 extends over andaround head 94 such that the head 94 of the implant 76 (and the ribs 96)are disposed within the interior 314 of the expandable member 312. Thedistal end of bore 102 opens into the interior 314 defined by the distalanchor 106 to receive the injectable material in a manner to bedescribed.

Returning to FIG. 1 and with concurrent reference to FIGS. 4-6, the tool30 includes a handle 32, sometimes called a housing. The handle 32 isshaped to have a barrel 34. In the illustrated embodiment, barrel 34 iscylindrically shaped. A handgrip 36, also part of the handle 32, extendsoutward from the barrel 34 adjacent the distal end of the barrel 34 toform a “pistol grip.” In the illustrated embodiment, the handgrip 36 iscylindrical in shape. Plural longitudinally spaced apart grooves 38extend circumferentially around the outer curved surface of the handle.The grooves 38 facilitate the grasping of the handle 32.

The barrel 34 is formed so that immediately forward of the proximal endthere is a slot 40. The slot 40 extends inwardly from andcircumferentially around the outer surface of the barrel 34. The handle32 is further formed so two coaxial bores extend between the opposedproximal and distal end of the barrel 34. A first bore, bore 42, extendsdistally forward from the proximal end of the barrel 34. The bore 42extends a length that is between 40% and 80% of the overall length ofthe barrel 34. A second bore, bore 44, extends forward from the distalend of bore 42 to the distal end of the barrel 34. The bore 44 has adiameter that is less than the diameter of bore 42. The bores 42 and 44are centered on the proximal to distal longitudinal axis 300 through thebarrel 34.

A first shaft 46 extends distally forward of the distal front end of thebarrel 34 and is defined by an outer diameter 48. The bore 44 extendsthrough the shaft 46 and is defined by an inner diameter 50. The innerdiameter 50 and outer diameter 48 may be approximately equal to, if notidentical to the inner and outer diameters of the base 79 of the cap 78.The distal end of the shaft 46 is formed to have a complementaryengagement feature, such as teeth 47, identified in FIGS. 1 and 6. Theteeth 47 are shaped to engage cap teeth 81. The shaft 46 may beintegrally formed with the barrel 34, or a separate component that issecured to the barrel 34.

A driver 52 is rotatably mounted to the handle 32. The driver 52includes a knob 54. The knob 54 is rotatably mounted around the proximalend of the barrel 34. Shown in FIG. 5, the driver 52 includes aninwardly-directed lip 56. The handle 32 is assembled so that the lip 56seats in, and is able to rotate in, the slot 40 formed in the barrel 34.The driver 52 is able to rotate within, but not move longitudinallyrelative to, the barrel 34. The driver 52 comprises a drive shaft 60(also referred to herein as a second shaft) integral with and extendingdistally forward from the knob 54 along the longitudinal axis 300. Thedrive shaft 60 has an outer diameter 330 that is less than an innerdiameter 50 of the shaft 46. The drive shaft 60 includes a shoulderportion 58 that extends distally forward from the distally directed faceof the knob 54. The shoulder portion 58 is shaped to closely slip fitand rotate in the bore 42 and has a diameter 334 larger than the outerdiameter 330. The drive shaft 60, which is smaller in outer diameterthan the shoulder portion 58, is shaped to closely slip fit and rotatein both the barrel 34 and the shaft 46. The components forming thehandle 32 are further constructed so that the distal end of the driveshaft 60 is located forward of a distal end of the first shaft 46. Alumen 62, identified in FIG. 6, extends longitudinally through thedriver 52 and has a diameter 332. The lumen 62 extends from theproximally directed face of the knob 54, through the drive shaft 60 tothe distal end of the drive shaft 60.

The driver 52 is further formed so immediately rearward of the opendistal end of the drive shaft 60, there is a drive feature, such asthreading 64, around the inner wall of the driver 52 that defines thelumen 62. The driver 52 is dimensioned so the distal end of the driveshaft 60 can seat in the annular space within the cap skirt 82, thelumen 62 can seat over the stem 88 and threading 64 can engage thethreading 89. The driver 52 is further formed so a delivery cannula 68,seen in FIGS. 4 and 5, can be slidably disposed in the lumen 62. Thesystem is further dimensioned so a distal end of the delivery cannula 68is sized to be seated in the counterbore 98 internal to the implant 76,for example, through an interference fit. In some embodiments, such asshown in FIG. 18, the delivery cannula 68 has a length defined betweenopposing ends with the length being such that when the implant 76 ispositioned within the borehole 126 the delivery cannula 68 extends abovethe skin 352 of the patient. The delivery cannula 68 may be used toverify the placement of the implant 76, and/or to inject the injectablematerial, discussed in further detail below.

To prepare tissue for receiving implant 76 of this disclosure, the firstand second tissue sections 122, 124 are aligned. A dashed line 123 marksthe approximate boundary between the outer relatively hard outer layerof cortical bone and softer internal layer of cancellous bone of thetissue or bone section 122 (it is also understood the second tissuesection may also include cortical and cancellous bone). Once the firstand second tissue sections 122, 124 are aligned, an incision may beprovided within the overlying tissue (e.g., skin, fascia and muscle),and the overlying tissue may be dilated with a suitable instrument toprovide a working channel to the first tissue section 122. A borehole126 is formed through at least a portion of the first and second tissuesections 122, 124. The borehole 126 may be formed so as to have anoverall length that is greater than the length of the implant. Moreparticularly, the borehole 126 may be formed so as to have a length suchthat when the proximal anchor 86 is deployed, the proximal anchor 86 maybe deployed within the portion of the cancellous bone adjacent thecortical bone. A closed distal end of the borehole 126 may be cored soas to create a cavity 128, for example, slightly larger than thediameter of the borehole 126. A cavity creator such as an expandableballoon tamp or a blade type cavity creator such as disclosed in PCTPub. No. WO 2010/017377/US Pat. Pub. No. US 2010/0036381, the contentsof which are explicitly incorporated herein may be used to form theborehole 126.

In certain embodiments, a guidewire (not shown) may be provided tofacilitate creation of the borehole 126. An access cannula 354 with anaccess needle 356 (see FIG. 14) disposed within the access cannula 354are directed through the incision 350 and the overlying tissue to dilatethe overlying tissue. The access needle 356 prevents coring of theoverlying tissue within the access cannula 354 as the access cannula 354and the access needle 356 are directed through the overlying tissue. Theaccess needle 356 (e.g., a trocar) is removed to provide the workingchannel through the overlying tissue to the first tissue section 122.The guidewire is directed through the working channel and intoengagement with the first tissue section 122. The access cannula 354 maybe removed with the guidewire remaining in engagement with the firsttissue section 122 and extending above the skin 352 of the patient.

The borehole 126 is then formed through at least a portion of the firstand second tissue sections 122, 124. In particular, a drill 358 (seeFIG. 15) is cannulated so as to slidably receive the guidewire. Thedrill 358 is directed through the incision 352 and the overlying tissuewhile constrained by the guidewire. The drill 358 is actuated (e.g.,rotated under manual or powered input) to create the borehole 126. Thedrill 358 is removed with the guidewire remaining in engagement with thefirst tissue section 122 and extending above the skin 352 of thepatient.

The implant 76 is removably coupled to the tool 30. In particular, thedistal end of the drive shaft 60 of the tool 30 is positioned within theskirt 82 integral of the implant 76. The knob 54 is rotated to cause thelike rotation of drive shaft 60. The rotation of the drive shaft 60causes the threading 64 to engage the threading 89 coupled to the stem88. The implant 76 is threaded onto drive shaft 60 until the teeth 81 ofthe cap 78 engage the complementary teeth 47 integral with tool 30, asseen in FIGS. 5 and 6. The engagement of teeth 47 with the teeth 81prevent the implant 76 from rotating relative to tool shaft 46.

The delivery cannula 68 may be inserted into the lumen 62. The deliverycannula 68 is optionally preloaded loaded with the injectable material.The cannula 68 is fitted in the lumen 62 so the distal end of thecannula 68 seats in counterbore 98 internal to the implant 76.

The tool 30 is used to position the implant 76 within the borehole 126.In certain embodiments, the tool 30 directs the implant 76 through theaccess cannula 352 and into the borehole 126. The implant 76 may bepositioned such that the proximal anchor 86 is located inward of theboundary 123 between the cortical and cancellous layers of the firsttissue section 122, and distal anchor 106 is located in the secondtissue section 124, for example, within the cavity 128. In embodimentsutilizing the guidewire (with the access cannula 352 removed), the tool30 and the implant 76 are cannulated so as to slidably receive theguidewire. The tool 30 and the implant 76 are directed through theincision 352 and the overlying tissue while constrained by theguidewire.

The proximal anchor 86 is deployed by actuating the driver 52. Thedriver 52 is actuated by rotating knob 54, and the rotation of knob 54results in a like rotation of drive shaft 60. It is understood that, atthis time, implant 76 is blocked from rotation relative to tool 30, andthe stem 88 is threadably engaging the drive shaft 60. Accordingly, therotation of drive shaft 60 draws the stem 88 proximally and, byextension, an entirety of the implant 76 moves proximally relative tothe tool 30. With movement of the cap 78 blocked by the abutment of thecap 78 against the distal end of shaft 46, the proximal anchor 86 iscompressed between cap 78 and trunk 90 of the implant 76. Owing to thepresence of apertures 104 localizing compressive stresses, thedeformable features 310 of the proximal anchor 86 is relativelymechanically weak. In other words, in response to longitudinallycompressive forces, the deformable features 310 of the proximal anchor86, in comparison to other sections of the implant 76, are less able toresist buckling. Accordingly, in response to the longitudinallycompressive force placed on anchor 86, the deformable features 310buckle outwardly. The deformable features 310 are adapted to buckle intotwo buckled sections separated by an elbow that projects radiallyoutwardly beyond the periphery 306 of trunk 90, as seen in FIGS. 8 and9. As a result of this buckling, the buckled sections and the elbow ofthe anchor 86 penetrate into the first tissue section 122 surroundingborehole 126. The penetration of the deployed anchor 86 into thesurrounding tissue prevents movement of the implant 76 relative to thefirst tissue section 122.

The distal anchor 106 is deployed. It is understood the deploying of thedistal anchor 106 may occur before or after deploying of the proximalanchor 86. The deploying of the distal anchor 106 may include expandingthe expandable member 312 with the injectable material. In one example,a stylet (not shown) is inserted into the lumen 62 to urge theinjectable material preloaded into the delivery cannula 68 to flowthrough bore 102 internal to the implant 76 and into the expandablemember 312. The injectable material is discharged from the open end ofbore 102 in into the interior 314 of the expandable member 312. Theinjectable material expands the expandable member 312 from the collapsedstate from which the expandable member 312 is within the periphery 306of the trunk 90, the expanded state in which at least a portion of theexpandable member 312 extend outwardly beyond the periphery 306 of thetrunk 90 relative to the longitudinal axis 300. The expandable member312 contacts and engages the second tissue section 124. The expandablemember 312 may compress the surrounding tissue against which theexpandable member 312. In embodiments utilizing the guidewire (with theaccess cannula 352 removed), the distal anchor 106 cannulated so as toslidably receive the guidewire. For example, the expandable member 312of the distal anchor 106 may be, for example, a torus or toroid definingan inner passageway through the expandable member 312. A suitablestructure may be coupled to the implant 76 to axially support thetoroidal expandable member at its distal end. For example, the neck 92(or an additional neck) may extend through substantially an entirely ofa length of the toroidal expandable member. In such an example, theinner passageway is sized to slidably receive the guidewire such that,as the tool 30 and the implant 76 are directed through the incision 352,the guidewire is disposed within the inner passageway of the expandablemember 312 prior to injecting the injectable material into the interior314 of the expandable member 312.

In embodiments where the injectable material is curable material, thecurable material may be permitted to cure or harden, resulting in a mass130 of cured material, shown in FIG. 9, extending outwardly from andaround the head 94 of the implant 76. Further, the curable materialhardens around the ribs 96 integral with head 94 and neck 92. Thehardening of the curable material around the ribs 96 reduces thelikelihood that, should the implant 76 and tissue section 124 besubjected to axial loads, the implant 76 will work free from thehardened mass 130 (e.g., “pull out”). The mass 130 and the expandablemember 312 prevent movement of the implant 76 relative to the secondtissue section 124. When the proximal and distal anchors 86 and 106engaging the first and second tissue sections 122, 124, respectively,relative movement between the tissue sections 122, 124 is prevented.

Once the implant 76 is deployed, driver 52 is actuated to disconnect thetool 30 from the implant 76. The knob 54 is rotated in the directionopposite the direction in which the knob 54 is rotated to deploy theproximal anchor 86. At this time, the proximal and distal anchors 86,106 constrain the implant 76 from movement relative to the tissuesections 122, 124. Accordingly, as a result of the rotation of driveshaft 60, the drive shaft 60 rotates proximally away from the stem 88.Since the drive shaft 60 does not move longitudinally relative to therest of the tool 30, the proximal movement of the tool 30 separates thetool from the implant 76. Subsequent steps of exemplary procedures willbe described in further detail.

Referring now to FIG. 10, an implant 142 in accordance with anotherexemplary embodiment is shown. In at least many respects the implant 142of the present embodiment is the same as that previously described. Theimplant 142 of FIG. 10 includes an elongate trunk 144 formed with one ormore recesses 146 that extend inwardly through a portion of the outersurface 308. The recesses 146 are sized to receive the injectablematerial(s). The recesses 146 are positioned between the proximal end302 and the distal end 304 of the trunk 144. The implant 142 may bepositioned within the patient such that the recess 146 is positionednear or adjacent the interface 326 between the first and second tissuesections 122, 124.

FIG. 11 shows an implant 152 in accordance with another exemplaryembodiment of the present disclosure. In at least many respects theimplant 152 of the present embodiment is the same as that previouslydescribed. The implant 152 of FIG. 11 includes the trunk 154 formed withone or more orifices 156 (one shown). The orifices 156 extend inwardlyfrom the outer surface of the trunk 154 and in fluid communication withbore 102. The implant 152 may be positioned within the patient such thatthe orifices 156 are positioned near or adjacent the interface 326between the first and second tissue sections 122, 124. In one example,when injectable material is injected into the bore 102, at least afraction of the injectable material flows out of the orifices 156. Inanother example to be described (see FIG. 13B), a cannula 190 may beselectively positioned to cause the injectable material to be directedthrough the orifices 156. It is contemplated that the orifices 156 ofFIG. 11 may be provided in addition to the recesses 146 of FIG. 10.

Referring now to FIG. 12, another exemplary implant 162 includes thetrunk 164 defining the bore 102. A valve 172 may be in communicationwith the distal end 160 of the bore 102, for example, coupled within thehead 168 of the implant 162. In the illustrated embodiment, the valve172 is a duck-billed valve. To facilitate the fitting of valve 172,internal to the head 94 of the trunk 164 there is a counterbore 160 withthe bore 102 opening into the counterbore 160. The counterbore 160 isshaped to receive the valve 172. The valve 172 is configured to allowfluid flow from bore 102 into the interior 314 within expandable member312 while blocking fluid flow in the reverse direction.

In certain embodiments, the injectable material may be introduced atdifferent locations along the length of the implant 76. This would allowthe injectable material to selectively be introduced into the distalanchor 106, through the orifices 156 in the trunk 90, and/or through theapertures 104 of the proximal anchor 86. FIGS. 13A, 13B and 13Cillustrate an implant 180 with which this type of cannula may be used.For clarity, the figures show the first and second tissue sections 124,124 spaced apart from one another. In at least many respects the implant180 of the present embodiment is the same as that previously described.The implant 180 of the present embodiment includes an elongate trunk 182with the orifice(s) 156 previously described. The implant 180 mayfurther include additional pathways 184 defined between the apertures104 of the proximal anchor 86 prior to or after buckling of thedeformable features 310.

A cannula 190 is slidably disposed in the bore 102 formed in trunk 182.It is to be understood that the delivery cannula 68 of FIG. 4 mayalternatively be used. The cannula 190 includes a proximal inlet portconfigured to be in fluid communication with a source of injectablematerial, and an outlet port 192. The cannula 190 may be formed so thedistal end of the cannula 190 is closed, and the outlet port 192 is aside port. For example, FIGS. 13A to 13C show the closed distal end andthe outlet port immediately proximal to the closed distal end.

The implant 180 may be suitably positioned within the first and secondtissue sections 122, 124. As seen in FIG. 13A, the cannula 190 isdirected through the bore 102 to position the outlet port 192 distal tothe head 94 and within the interior 314 of the expandable member 312 a.The curable material is flowed through the cannula 190 and outlet port192 into the expandable member 312 a. The injectable material firstexpands the expanding portion 110 a of the expandable member 312 a.Since expandable member 312 a is formed with pores 178 (and/orfenestrations), the continued flow of curable material into theexpandable member 312 a causes the curable material to flow out of thepores 178 and into the borehole 126 and the surrounding surface of thesecond tissue section 124. Subsequent to the curable material curingexternal to the expandable member 314, within the interior 314, andthrough the pores 178 (and/or fenestrations), the interaction (e.g.,retention) of the distal anchor 106 and the second tissue section 124 isimproved.

Referring now to FIG. 13B, the cannula 190 is axially positioned so theoutlet port 192 is in fluid communication with the orifice 156.Material(s) to be introduced into the interface 326 or joint spacebetween the sections of first and second tissue sections 122, 124. Forexample, the injectable material may be the curable material, the bonegrowth material, and/or the therapeutic agent. It is understood that theinterface 326 or joint space is comprised of cartilaginous material withsynovial space not particularly conductive to receiving injectedmaterial. In certain exemplary methods, anatomy from the interface 326or joint space may be removed prior to injecting the material(s). Forexample, the joint space may be decorticated (i.e., removing outerlayers of cartilage to expose the surfaces of the first and secondtissue sections 122, 124). The decortication may be performed with amechanical instrument such as a curette. The instrument may be directedthrough a portion of the borehole 126 and into the interface 326 priorto positioning the implant 76 within the borehole 126 (e.g., during orsubsequent to creation of the borehole 126). In another example, aworking end of instrument may be sized to be extend through theorifice(s) 156 of the implant 76. With the implant 76 suitablypositioned within the borehole 126, the working end of the instrument isdirected through the orifice(s) 156 to decorticate the interface 326.The implant 76 may be rotated within the borehole 126 (with the proximaland distal anchors 86, 106 in the initial configuration and collapsedstate, respectively) with the working end of the instrument extendthrough the orifice(s) 156 to decorticate the interface 326. With thesurfaces of the first and second tissue sections 122, 124 exposed, theinjected material(s), for example the bone growth material, directlycontacts the bone surfaces to promote bone growth and fusion.

The cannula 190 may be positioned so that outlet port 192 is placed influid communication with the orifice 184, as shown in FIG. 13C. Theinjectable material may be introduced to the additional pathways 184defined between the apertures 104 of the proximal anchor 86 prior to orafter buckling of the deformable features 310. In one example, theadditional curable material introduced through the pathways 184, uponhardening, strengthens the fixation of the proximal anchor 86 to thefirst tissue section 122. Further, it is contemplated that the cannula190 may be replaced with another cannula to inject different types ofmaterials to different locations along the length of the implant 180.

FIGS. 14-18 show several steps of an exemplary method for preventingrelative motion between the first and second tissue sections 122, 124.The first tissue section 122 is hereinafter referred to as the ilium122, and the second tissue section 124 is hereinafter referred to as thesacrum 124 of the patient. The implant 76 is implanted using a minimallyinvasive procedure. First, a minimally invasive incision 350 (see FIG.18) is created in the skin 352 of the patient. The incision 350 may beformed with a scalpel, the access needle 356 disposed inside the accesscannula 354, or by other methods. The access cannula 354 with the accessneedle 356 is directed through the overlying soft tissue towards theilium 122. The overlying soft tissue is dilated, and a distal end of theaccess cannula 354 is positioned near or adjacent the ilium 122 as shownin FIG. 14. The access needle 356 may be removed to provide a workingchannel through the access cannula 354 to the ilium 122.

As previously described, the guidewire (not shown) may be provided tofacilitate creation of the borehole 126. The guidewire is directedthrough the working channel and into engagement with the ilium 122. Theaccess cannula 354 may be removed with the guidewire remaining inengagement with the ilium 122 and extending above the skin 352 of thepatient. The drill 358, the tool 30, and the implant 76 being cannulatedto receive the guidewire with the subsequent steps performed with theaccess cannula 354 removed.

Referring to FIG. 15, the drill 358 is inserted through the accesscannula 354 to engage the ilium 122. The drill 358 is operated to resectthe borehole 126 through the ilium 122 and into the sacrum 124, afterwhich the drill 358 is removed from the access cannula 354. FIG. 15shows the drill with a handle configured to be hand-operated, but it isunderstood that powered drills, burs, shavers, and the like, may be usedto resect the borehole 126.

FIG. 16 shows the tool 30 is provided with the implant 76 removablycoupled to the distal end of the shaft 46. In some embodiments, a singletool 30 is used throughout the procedure and the method may include astep of removably coupling the implant 76 to the tool 30. In thisembodiment, the tool 30 is operated by applying a torque to the driver52 in a first direction to engage drive features (e.g., the threads 64),of the drive shaft 60 of the tool 30 with complimentary driven features(e.g., the threads 89) coupled to the stem 88. The tool 30 is furtheroperated to engage engagement features, such as teeth 47, coupled to theshaft 46 of the tool 30 with complimentary engagement features (e.g.,the teeth 81) coupled to the trunk 90 to prevent rotation of theproximal anchor 86 relative to the shaft 46 and prevent an axialmovement of the proximal end of the proximal anchor 86 relative to theshaft 46. Further, the delivery cannula 68, which is coaxially disposedwithin the lumen 62 is placed in fluid communication with the bore 102.

FIGS. 16 and 17 illustrate the steps of positioning the implant 76within the borehole 126 such that the proximal anchor 86 is disposed inthe ilium 122 and the distal anchor 106 is disposed in the sacrum 124,and operating an insertion tool 30 to apply a compressive force to theproximal anchor 86 along the longitudinal axis 300 to move the proximalanchor 86 from the initial configuration to the deployed configuration.The implant 76 may be positioned within the borehole 126 such that theexpandable member 312 is disposed within the cancellous bone of thesacrum 124. Prior to applying the compressive force to the proximalanchor 86, the deformable feature 310 is within the periphery 306 of thetrunk 90. The compressive force is applied by rotating the knob 54 in afirst direction (represented by the arrow shown in FIG. 17). Therotation of the knob 54 in turn rotates the drive shaft 60, which due tothe engagement of the threads 64 on the drive shaft 60 and the threads89 on the stem 88, the stem 88 is drawn into the lumen 62. Becauserotation of the proximal anchor 86 relative to the shaft 46 and axialmovement of the proximal end of the proximal anchor 86 relative to theshaft 46 is prevented, the compressive force is applied to thedeformable feature 310. The compressive force deforms the deformablefeature 310 such that at least a portion of the deformable feature 310extends outwardly beyond the periphery 306 of the trunk 90 relative tothe longitudinal axis 300 to engage the ilium 122.

Once the proximal anchor 86 is engaged and maintaining the position ofthe implant 76 relative to the ilium 122, the tool 30 may be decoupledfrom the implant 76. A torque is applied to the driver 52 of the tool 30in a second direction opposite to the first direction (represented bythe arcuate arrow shown in FIG. 18) to rotate the drive shaft 60. Theproximal anchor 86 is in the deployed configuration and engaging theilium 122, and rotation of the drive shaft 60 decouples the threads 64from the complimentary threads 89 of the implant 76. When the distal endof the shaft 46 of the tool 30 is decoupled from the implant 76, thedelivery cannula 190 (or the delivery cannula 68) remains coupled to theimplant 76 positioned within the borehole 126, as shown in FIG. 18. Thepresence of the delivery cannula 190 extending above the incision 350 inthe skin 352 provides visual indication to the surgeon of the presence,location, and orientation of the implant 72 within the patient.

After the proximal anchor 86 is engaged and maintaining the position ofthe implant 76 relative to the ilium 122, the distal anchor 106 isengaged with the sacrum 124. The injectable material is injected fromthe source of injectable material. In order to inject the injectablematerial, an injectable material delivery system 360 includes or iscoupled to the source of injectable material. One such injectablematerial delivery system 360 is shown in FIG. 18. The injectablematerial delivery system 360 is coupled to the cannula 190 such thatinjectable material injected into the cannula 190 flows through the bore102 and into the interior 314 of the expandable member 312. Theinjectable material moves the expandable member 312 between thecollapsed state in which the expandable member 312 is within theperiphery 306 of the trunk 90, and the expanded state in which at leasta portion of the expandable member 312 extends outwardly beyond theperiphery 306 of the trunk 90 relative to the longitudinal axis 300.Owing to the porosity of the cancellous bone, the expandable member 312(and in certain embodiments the injectable material directed throughporous features or fenestrations 178 of the expandable member 312),displace blood and marrow forming the cancellous bone. In embodimentswhere the injectable material is curable material, the curable materialis permitted to cure within the interior 314 of the expandable member312 with the expandable member 312 engaging the sacrum 124.Additionally, the curable material injected into the interior 314 of theexpandable member 312 surrounds the neck 92 and is in contact with therib 96. The curable material is permitted to cure in contact with therib 96 to facilitate axial retention of the implant 76 within the curedcurable material.

In some embodiments of the method, the expandable member 312 comprisesfenestrations 178. In this embodiment the method further comprises astep of injecting additional curable material into the interior 314 ofthe expandable member 312 such that a portion of the curable material isurged through the fenestrations 178 and into contact with the sacrum124. In another embodiment of the method, the expandable member 312 isformed from a permeable material. In this embodiment the method furthercomprises a step of injecting additional curable material into theinterior 314 of the expandable member 312 such that a portion of thecurable material is urged through the permeable material and intocontact with the sacrum 124.

In some embodiments of the method, multiple implants 76 may be implantedinto a patient. As mentioned above, each implant 76 may have asdedicated tool 30, or a single tool 30 may be used to insert multipleimplants 76. The method further comprises the step of decoupling thetool 30 from a first implant, and removably coupling the tool 30 to asecond implant. With continued reference to FIG. 18, the second implantis then inserted through a second minimally invasive incision and withina second borehole with a proximal anchor of the second implant engagingthe ilium 122 and a distal anchor of the second implant disposed in thesacrum 124. The proximal anchor of the second implant is then deployedin a manner substantially the same as the first implant. Prior to boththe first implant and second implant receiving the injectable material,the second implant is decoupled from the distal end of the shaft 46 ofthe installation tool 30 with a second delivery cannula remainingcoupled to the second implant positioned within the second borehole. Thedelivery cannulas coupled to the first and second implants extendthrough the first and second minimally invasive incisions, respectively.The injectable material is then injected into each delivery cannula toexpand the expandable member of the first implant and the secondimplant.

After expanding the expandable member 312 of the one or more implants 76outwardly to engage the sacrum 124, the delivery cannula 68 and theaccess cannula 354 are each removed through the minimally invasiveincision 350. Finally, the minimally invasive incision 350 is closedwith the expandable member 312 and cured curable material remainingwithin the patient.

The foregoing is directed to specific versions of the disclosure. Otherfeatures of the stabilization system and/or the implant arecontemplated. For example, the shapes of the components of the implant76 may vary from what has been described. In alternative versions of thedisclosure the trunk 90 may be non-circular in cross section. In some ofthese versions of the disclosure the trunk 90 may be formed so as tohave straight edges that meet at corners. A benefit of providing thetrunk 90 with non-circular cross-sectional shapes is that it can serveto limit the rotation of the implant 76 in the tissue in which theimplant 76 is seated. In certain embodiments, certain structures of theimplant 76 may be formed of unitary construction (e.g., the trunk 90 andthe cap 78). Likewise, for ease of manufacture, it may be desirable toform the trunk 90 out of coaxial inner and outer tubes. Further, incertain embodiments, the trunk 90 may be curved or angled along a curvedlongitudinal axis 300. This feature may be useful to facilitateplacement of the implant 76 or the mechanical properties of the implant76. In certain embodiments, one or both of the proximal and distalanchors 86, 106, may be configured to deploy asymmetrically. This wouldbe particularly suitable for applications where space considerations arepresent in the intended area of the implant. Additionally oralternatively, the implant 76 may be configured to withstand asymmetricmechanical loading. In certain embodiments, the proximal and distalanchors 86, 106 of the implant 76 of may be configured to be deployedeither simultaneously or sequentially.

In certain embodiments, the proximal anchor 86 may not extend beyond theperiphery 306 in the deployed configuration, and/or the distal anchor106 may not extend beyond the periphery 306 in the expanded state. Thedeployed configuration and the expanded state may be alternativelydefined as the proximal anchor 86 and the distal anchor 106,respectively, simply moving radially outwardly from the longitudinalaxis 300 of the trunk 90 (even if not beyond the periphery 306).

The proximal anchor 86 may be of any suitable construction. For example,a screw-like member may be provided with a threaded shaft having apointed tip. The screw-type member is deployed by rotating the anchor sothe shaft threads into the bone. The shaft threading engages the bone tosecure the anchor and, by extension, the implant to the bone. Foranother example, one or more rigid pins may be provided to deploy bybeing forced outwardly from the trunk. Another alternative includes aspring that is under tension with the anchor deployed by releasing amember restraining the spring.

Likewise, the distal anchor 106 may be of any suitable construction. Incertain embodiments, the expandable member 312 is formed from anon-compliant material that inflates to a defined shape. An example of anon-compliant material is a synthetic textile such as woven polyesterfabric. An outer surface of the expandable member 312 may be impregnatedwith materials. One such material may be a material to encourage bonegrowth, and another material may include the therapeutic agent (e.g., amaterial that reduces the likelihood of infection). It should beunderstood that that the distal anchor may take the form of an outwardlybuckling assembly and the proximal anchor take the form of an inflatableexpandable member.

The tool 30 may include the additional and/or alternative components fordeploying the implant 76. These components may include solid shafts thatare moved longitudinally relative to the tool handle 32. Each shaft isadvanced or retracted to deploy the anchor that the shaft engages.Likewise, other means than threading may be used to releasably hold theimplant 76 to the tool 30. For example, for some versions of thedisclosure, the tool 30 may be formed with fingers that retract orcontract. The implant 76 is formed with complementary openings forreceiving the distally located tips of these fingers. Once the implant76 is set the fingers are retracted or contracted away from the openingsin which they are seated so as to disconnect the tool 30 from theimplant 76.

The cannula (e.g., the delivery cannula 86 or the cannula 190) itselfmay be comprised of a flexible material to allow the cannula to exit theopening and deliver injectable material distally of the implant 76through that opening. For example, cannula may be comprised of asuperelastic metallic material, such as nitinol, that possesses a presetcurved shape that allows it to exit the opening in the implant 76 anddeliver injectable material to a tissue location a certain distance awayfrom the implant 76. It is further contemplated that another instrumentmay be deployed through the bore 102, for example, a curette that isused to form a cavity around the implant 76.

Variations in the above described exemplary methods are alsocontemplated. The borehole 126 in which the implant is fitted may have adiameter equal to or less than the diameter of the trunk 90 of theimplant 76. For example, the diameter of the borehole 126 is less thanthe diameter of the trunk 90, by 1 mm or less. In such an example, thereis a compression or interference fit between the trunk 90 and the tissuesurrounding the trunk 90. In certain methods, the tool 30 are arrangedto hold the trunk 90 of the implant 76 static while the tool 30 isadvanced distally (as opposed to retracted proximally) to provide thecompressive force to induce buckling of the proximal anchor 86. Further,it is also contemplated that the adjacent sections of soft tissue may besecured together. For example, the implant 76 may include one or morebarbs.

The foregoing is directed to specific versions of the disclosure. Otherversions of the disclosure may have different features. It shouldlikewise be understood that not all versions of the disclosure may haveeach of the above described features. Likewise, the features of thedifferent versions of the disclosure may be combined. Accordingly, it isan object of the appended claims to cover all such variations andmodifications that come within the scope of this disclosure.

1-54. (canceled)
 55. An implant for a minimally invasive bonestabilization system for preventing relative motion between an ilium anda sacrum, said implant comprising: an elongate trunk comprising aproximal end configured to be positioned within the ilium, a distal endconfigured to be positioned within the sacrum such that said elongatetrunk extends between the ilium and the sacrum, a bore extending throughsaid elongate trunk along a longitudinal axis defined between saidproximal and distal ends, and a periphery defined by an outer surface ofsaid elongate trunk; a proximal anchor extending proximally from saidelongate trunk and comprising at least one deformable feature adapted todeform in response to a compressive load to move said proximal anchorfrom an initial configuration in which said deformable feature is withinsaid periphery of said elongate trunk, to a deployed configuration inwhich at least a portion of said deformable feature extends outwardlybeyond said periphery of said elongate trunk relative to saidlongitudinal axis to engage the ilium; and a distal anchor coupled tosaid elongate trunk opposite said proximal anchor and comprising anexpandable member defining an interior in fluid communication with saidbore of said elongate trunk such that said distal anchor is configuredto be deployed by said expandable member receiving injectable materialthrough said bore with said proximal anchor in said deployedconfiguration to move said distal anchor from a collapsed state in whichsaid expandable member is within said periphery of said elongate trunk,to an expanded state in which at least a portion of said expandablemember extends outwardly beyond said periphery of said elongate trunkrelative to said longitudinal axis to engage the sacrum.
 56. The implantof claim 55, wherein said elongate trunk is substantially cylindricaland comprising a diameter, wherein said implant further comprises a neckextending distally from said distal end of said elongate trunk with saidexpandable member coupled to said neck, wherein said neck comprises adiameter less than said diameter of said elongate trunk to provide spaceto accommodate said expandable member within said periphery in saidcollapsed state.
 57. The implant of claim 56, further comprising and atleast one rib coupled to and extending radially outwardly from said necksuch that, with said expandable member coupled to said neck, said rib islocated within said interior of said expandable member.
 58. The implantof claim 55, wherein said expandable member further comprisesfenestrations configured to permit the received injectable material topass through said fenestrations into the sacrum.
 59. The implant ofclaim 55, wherein said proximal anchor further comprises a plurality ofapertures defining said at least one deformable feature interposedbetween each adjacent pair of said apertures, wherein said apertures areconfigured to localized stresses to said deformable feature from thecompressive loads to induce the deformation of said deformable feature.60. The implant of claim 59, further comprising a stem extendingproximally from said proximal end of said elongate trunk and comprisinga diameter less than said diameter of said elongate trunk, and drivenfeatures configured to engage complimentary drive features of aninsertion tool.
 61. The implant of claim 55, further comprising anorifice extending through said outer surface of said elongate trunk andin fluid communication with said bore with said orifice configured todeliver material between the ilium and sacrum.
 62. The implant of claim55, further comprising an recess extending inwardly through a portion ofsaid outer surface of said elongate trunk and sized to receive tissuegrowth-promoting material with said recess between said proximal anddistal ends such that, with said proximal end positioned in the iliumand said distal end positioned within the sacrum, said recess configuredto provide the tissue growth-promoting material between the ilium andthe sacrum.
 63. The implant of claim 55, wherein said expandable memberis a flexible, inflatable balloon.
 64. An implant for a minimallyinvasive bone stabilization system for preventing relative motionbetween an ilium and a sacrum, said implant comprising: an elongatetrunk comprising a proximal end configured to be positioned within theilium, a distal end configured to be positioned within the sacrum suchthat said elongate trunk extends between the ilium and the sacrum, abore extending through said elongate trunk along a longitudinal axisdefined between said proximal and distal ends, and a periphery definedby an outer surface of said elongate trunk; a proximal anchor extendingproximally from said elongate trunk and comprising at least onedeformable feature adapted to deform in response to a compressive loadto move said proximal anchor from an initial configuration in which saiddeformable feature is within said periphery of said elongate trunk, to adeployed configuration in which at least a portion of said deformablefeature extends outwardly beyond said periphery of said elongate trunkrelative to said longitudinal axis to engage the ilium; and a distalanchor coupled to said elongate trunk opposite said proximal anchor andcomprising an expandable member defining an interior in fluidcommunication with said bore of said elongate trunk such that saiddistal anchor is configured to be deployed by said expandable memberreceiving injectable material through said bore to move said distalanchor from a collapsed state in which said expandable member is withinsaid periphery of said elongate trunk, to an expanded state in which atleast a portion of said expandable member extends outwardly beyond saidperiphery of said elongate trunk relative to said longitudinal axis tobe cured with said expandable member displacing cancellous bone of thesacrum.
 65. The implant of claim 64, further comprising and at least onerib coupled to and extending radially outwardly from said neck suchthat, with said expandable member coupled to said neck, said rib islocated within said interior of said expandable member.
 66. The implantof claim 64, wherein said expandable member further comprisesfenestrations configured to permit the received injectable material topass through said fenestrations into the sacrum.
 67. A method forpreventing relative motion between an ilium and a sacrum with an implantincluding an elongate trunk having opposed proximal and distal endsdefining a longitudinal axis, a periphery defined by an outer surface,and a bore extending through the elongate trunk, the implant furtherincluding a proximal anchor, and a distal anchor including an expandablemember defining an interior in fluid communication with the bore, saidmethod comprising the steps of: creating a minimally invasive incisionwithin skin; positioning an access cannula through the minimallyinvasive incision; resecting a borehole through the ilium and into thesacrum through the access cannula; positioning the implant within theborehole such that the proximal anchor is disposed in the ilium and thedistal anchor is disposed in the sacrum; operating an insertion toolremovably coupled to the implant to apply a compressive force to theproximal anchor along the longitudinal axis to move the proximal anchorfrom an initial configuration in which the proximal anchor is withinsaid periphery of the elongate trunk to a deployed configuration inwhich at least a portion of a deformable feature of the proximal anchorextends outwardly beyond the periphery of said elongate trunk relativeto the longitudinal axis to engage the ilium; and injecting injectablematerial through the bore and into the expandable member to move theexpandable member between a collapsed state in which said expandablemember is within the periphery of the elongate trunk, to an expandedstate in which at least a portion of said expandable member extendsoutwardly beyond the periphery of the elongate trunk relative to saidlongitudinal axis to engage the sacrum.
 68. The method of claim 67,wherein said step of operating the tool to apply the compressive forceto the proximal anchor further comprises the steps of: operating thetool to engage drive features of a first shaft of the tool withcomplimentary driven features coupled to the elongate trunk; operatingthe insertion tool to engage engagement features coupled to a secondshaft of the tool with complimentary engagement features coupled to theelongate trunk to prevent rotation of the proximal anchor relative tothe second shaft and prevent an axial movement of a proximal end of theproximal anchor relative to the second shaft; applying a torque to theinsertion tool in a first direction to rotate the first shaft and drawthe driven features proximally such that, with rotation of the proximalanchor and axial movement of the proximal end of the proximal anchorprevented, the compressive force is applied to the proximal anchor alongthe longitudinal axis.
 69. The method of claim 67, wherein said step ofmoving the proximal anchor from the initial configuration the deployedconfiguration is performed prior to the step of injecting the injectablematerial into the expandable member.
 70. The method of claim 67, whereinthe implant further comprises an orifice extending through the outersurface of the elongate trunk and in fluid communication with the bore,wherein the method further comprises the steps of: positioning theimplant within the borehole with the orifice approximately positioned atan interface between the ilium and the sacrum; and injecting additionalinjectable material through the orifice.
 71. The method of claim 67,further comprising the step of decoupling the insertion tool from theimplant by applying a torque to the insertion tool in a second directionopposite to the first direction to rotate the first shaft such that,with the proximal anchor in the deployed configuration and engaging theilium, rotation of the first shaft decouples the drive features from thecomplimentary driven features of the implant.
 72. The method of claim67, wherein the injectable material is curable material, said methodfurther comprising the step of allowing the curable material to curewith the expandable member engaging the sacrum in the expanded state.73. The method of claim 72, wherein the expandable member is formed frompermeable material, said method further comprising the step of injectingadditional curable material into the expandable member such that aportion of the curable material is urged through the permeable materialinto the sacrum.
 74. The method of claim 67, wherein the sacrum includesan exterior cortical bone wall and interior cancellous bone region, saidmethod further comprising the steps of: positioning the implant withinthe borehole with the expandable member disposed within the interiorcancellous bone region; and performing the step of injecting theinjectable material into the expandable member with the expandablemember disposed within the interior cancellous bone region.